That 25% cdr is sure nice... But other than that, i haven't seen much of that rune used by players. The effect is too occasional. On very rare occasion you would switch flash for let's say, cleanse or ghost. Idk, that's what I think
Retocyn4 votesI take it to cheese with 
on the blue side against a jungler who wants to start blue. I start with 
+ 
, try to steal their blue, or just mess with them so their clear is slower, or force them to use their smite inefficiently. (I'm an evil, I know)
If I happen to steal the blue - great! I can spam grabs in lane, also - I can Q smite a minion to catch some people off-guard. Once I recall, I change to 
and go for all-ins with ult and the Hex-Flash to hopefully again, catch people off-guard.
If there's an important dragon and we (as a botlane) are really ahead, or I know that our jungler doesn't really care about objectives, I'll go again to secure objectives.
When I'm done with the and I go for 
for a different form of aggressiveness, there's nothing enemy ADC can do if I run with + W to E them, then R and Q. Doesn't matter that my is on cooldown at that point.
However, in the late game, I tend to switch to 
to help my ADC stay alive since we have such a snowbally meta right now and lots of assassins are being picked.
I had success with this build so far, if the game goes well, I'm using all the shards at the time, but if I get behind, it doesn't feel as good, or I fail to use it properly.
GeminiRune1 votesThat's the creativity I like about the Rune. And your strat is somewhat exactly what I tend to do as a starter. Carry the Smite and hover around a camp that could be smote for health by the enemy jungler before going to lane.
That and so I have the capability to buy the jungle items if need be and then swap it out on first back because if I'm not jungling why do I need it early game other than to smite some cannons because my last hitting is ass? I'll just pick it back up late game if I decide to buy a Bloodrazor on my ADC.
Escheton1 votesI can only see it work on like...Toplane Cinderhulk Sion/Cho or thing like a Singed starting ghost-ignite for lvl 2 cheese, then swapping to tp later.
FlatEarth Jacois1 votesI've been using Unsealed Spellbook to great success (in my opinion) with Bard. Admittedly I rarely swap, but it's the 25% cooldown on the summoners that I'm after. With Boots of Lucidity that's 40% cd on my Summoner Spells. Bard is so good at sniping low hp targets with flash and ignite up, that it's extremely valuable.
I will occasionally swap the ignite for teleport if flash is down.
Quepha1 votesI have. Someone I played with completely took over the game as Karthus support because his exhaust was up for every single fight. He just sat around farting out damage and anyone that dove him would eat an exhaust and die.
I'm also OK with Inspiration having a keystone that's just weird, niche, and very rarely seen.
Ashe mage AD1 votesYou want it on Zyra or Annie support so you can flash on them every so often with your ult. Or any supports really that have a good flash ult engage. You can get it to a max of 40% with 25% + 5% from runes and another 10% from boots and it's real good, I had fun testing it. It's kinda yolo but they don't really expect it; not so frequently anyhow, you can have the 15% ult cdr + 10% free regular cdr along with it also which I also took.
Another good perk you get out of it is you can start the game with ignite and later switch to exhaust if needed.
Hochelaga1 votesDoes it reduce hextech flash by 25% too?
Proxy3451 votesThats because the game is in dire need of new summoner spells lol
MeltedWater1 votesI tried it on Karthus top, and have to say, I like it. Start with Exhaust, to help keep yourself alive or get a kill. Swap to Teleport when needed. Hell, at one point I gave up Flash to have both. The potential is there for Cleanse or Ignite or Smite if needed. Just having 25% CDR is nice.